Energy and protein levels in diets containing phytase for broilers from 22 to 42 days of age: performance and nutrient excretion

Abstract

-This study was conducted in order to evaluate the influence of different levels of metabolizable energy and crude protein in diets formulated according to the ideal protein concept with phytase supplementation on performance and nutrient excretion of broilers from 22 to 42 days age. It was used 1,500 Coob lineage broilers at 22 days of age and with initial weight of 833 ± 7g, distributed in completely randomized design in a 3 × 3 + 1 factorial scheme composed of three levels of correct apparent metabolizable energy (2,950; 3,100 and 3,250 kcal/kg), three levels of crude protein (14, 16 and 18%) and a control treatment, totaling ten treatments with six repetitions of 25 birds each. All diets, with the exception of the control, were supplemented with phytase. For determination of excretion of pollutants, it was used 180 broilers from the same lineage at 35 days of age,placed in metabolic cages, with ten treatments each one with six repetitions and three birds per experimental unit. The protein and energy levels in diets containing phytase influenced feed intake, weight gain, feed conversion and excretion of nitrogen, phosphorus, calcium, potassium, copper and zinc by the birds. The corrected apparent metabolizable energy level in the diets for broilers in the studied period must be increased up to 3,250 kcal/kg of metabolizable energy and the levels of crude protein, calcium and phosphorus must be reduced down to 18, 0.70 and 0.31%, respectively, provided that supplemented with amino acids and phytase to improve the performance and to reduce excretion of pollutants by birds.

Effects of phytase supplementation on growth performance, slaughter performance, growth of internal organs and small intestine, and serum biochemical parameters of broilers

“…Compared with broilers which diets do not supplement phytase, the growth rate and feed conversion ratio are improved with the low-P diets containing microbial phytase. Nagata et al [5] has reported that phytase can improve the growth performance and nutrient utilization of broilers.…”

Comparison of Methodologies to Quantify Phytate Phosphorus in Diets Containing Phytase and Excreta from Broilers

“…Although the economic and environmental benefits obtained through the use of phytase in broiler diets are reported in the literature ( Nagata et al, 2011 ; Santos et al, 2011a , b ; Gomide et al, 2012 ), its catalytic efficiency to make the phytate phosphorus (P phy ) of the feed available is not yet well established, and, according to Angel et al (2002) , this should be done while considering the P phy concentration in both the feed and the excreta. Among the analytical methods used for the phytate determination, those that utilize colorimetric and refraction principles stand out ( Wu et al, 2009 ).…”

Efficiency of microbial phytase supplementation in diets formulated with different calcium:phosphorus ratios, supplied to broilers from 22 to 33 days old

“…The use of phytase in broiler diets is nutritionally, environmentally and economically viable (Gomide et al., ; Santos et al., ; Silva et al., ; Nagata et al., ). Therefore, the broiler feeds in current use have been formulated with low levels of available phosphorus (P avail ) and supplemented with microbial phytase.…”